MASTODON ANGUSTIDENS. 213 
teeth of the typical species of Mastodon are compared with 
those of the Elephants, in reference to their structure. 
The dentine, or principal substance of the crown of the 
tooth, is covered by a very thick coat of dense and brittle 
enamel; a thin coat of cement is continued from the fangs 
upon the crown of the tooth, but this third substance does 
not fill up the interspaces of the divisions of the crown, as 
in the Elephants. Such, at least, is the character of the 
molar teeth of the first discovered species of Mastodon, 
which Cuvier has termed Mastodon giganteus, and Mas- 
todon angustidens. Fossil remains of proboscidians have 
subsequently been discovered, principally in the tertiary 
deposits of Asia, in which the number and depth of the 
clefts of the crown of the molar teeth, and the thickness 
of the intervening cement, are so much increased as to 
establish transitional characters between the lamello-tuber- 
culate teeth of Elephants, and the mammillated molars of 
the typical Mastodons ;* showing that the characters de- 
-ducible from the molar teeth are rather the distinguishing 
marks of species than of genera, in the gigantic probos- 
cidian family of mammalian quadrupeds. 
* Mr. Clift had foreseen the possibility of the discovery of such a link, since 
supplied by the praiseworthy exertions of Captain Cautley, and Dr. Falconer ; and 
in his description of the Fossil Remains from Ava, in the Geological Transactions, 
second series, yol. ii., he says, “ It is not impossible that there may yet be 
a link wanting, which might be supplied by an animal haying a tooth composed 
of a greater number of denticles, increasing in depth, and having the rudiments 
of erusta petrosa, that necessary ingredient in the tooth of the Elephant: the en- 
tire absence of which distinguishes the tooth of the Mastodon.” Cuvier had pre- 
viously enunciated the same supposed distinctive character between the struc- 
ture of the teeth of the Elephant and Mastodon. “ Dans l’éléphant ces vallons 
sont entierement comblés par /e cortical, tandis que dans le Mastodonte ils ne sont 
remplis de rien.” Ossemens Fossiles, tom. i. 4to, 1821, p. 225. Mr. S. Wood- 
ward put forth a more remarkable, but not less erroneous opinion on this subject. 
He says, “ The distinctive characters of the grinders of the Elephant and Mas- 
todon are so decided, that it is scarcely possible to mistake the one for the 
other. The enamel of the former is disposed in pairs transversely, to the num- 
iT: 
